TORONTO—Fairfax Financial Holdings Ltd. disclosed that its partners in a $1 billion investment in struggling smartphone maker BlackBerry Ltd. include a Qatar-based sovereign-wealth fund and several Canadian investment funds.

Fairfax's regulatory filing Thursday answers some of the questions that have hovered over BlackBerry since it scrapped a monthslong attempt to sell itself on Monday, saying it would continue as a public company with new leadership and the $1 billion investment.